solve for x on the domain 0<x<12: cos x =- 0.814

Answer 1

if x is measured in degrees, then 0<x<12 degrees

x = cos^-1(-.814) = about 144.5 degrees which is not in the interval (0,12)

there is no solution

if x is measured in radians then 0<x<about 687.55 degrees, then

x= 144.5, 215.5, 504.5, 575.5 degrees

4 solutions, all in quadrants II or III